BMW checks bumpers with the wave of a hand

Quality control is a vital part of modern manufacturing. Not only does it decrease the chances of a dissatisfied customer, but it reduces waste and, therefore, cost. However, inspecting products on the assembly line can itself be expensive, time consuming, and not as accurate as it should be. To speed things up a bit, BMW has developed a new system for inspecting bumpers that uses gestures to allow inspectors to literally point out defects.

In the old days, quality control on a car assembly line involved a worker with a marker pen pointing out flaws on bumpers or body panels by drawing circles or making notes. It worked, but there was always the danger of the mark being overlooked down the line, or being misunderstood.

The current system is one that relies on a worker inspecting a bumper and entering the information into a computer workstation. On the surface, it’s much more efficient than making marks, but it's still tiring and means turning away from the bumper, which increases the chances of error. In addition, the operator can get distracted, or if the bumper has a number of things wrong with it, there’s a greater chance of forgetting details before they can be recorded.

The BMW solution, developed with the Fraunhofer Institute in Karlsruhe and tested at the BMW Landshut plant in Munich, uses what the company calls the “Fourth Industrial Revolution” that merges the virtual and real world. In this system, bumpers leave the paint shop and go to a quality control station. There, using gesture recognition technology similar to that developed for video games, the operator points out defects in the bumper by pointing at them.

It works by means of an infrared light system that projects a grid over the bumper while a pair of 3D cameras monitor the grid and recognizes and records gestures. A wiping motion indicates that the bumper is flawless, while pointing indicates that there is a flaw at the coordinates indicated. This way, flaws can be recorded without the operator turning away from the bumper, which makes quality control faster and more accurate. In addition, BMW says that the system doesn’t require special glasses, gloves, or microphones.

"The workers have responded very positively to the new technology," says project coordinator Ramona Tremmel. "The gesture interaction is simple and easy to understand and can be applied intuitively, without requiring extra training time. People do not have to walk to other workstations anymore and can concentrate better on their work."

A pilot program has been completed and BMW says that the technology is being adapted for production purposes.